> | But it is a pain to be unable to use sshd with a read-only filesystem.
> But having dev readonly does not really work, does it? What happens
> when you try to write to /dev/null?

It works. Having the fs read-only does not mean you cannot write to
devices:

root@violette[/root]#mount -o ro /dev/sd0a /
root@violette[/root]#dd if=/dev/zero of=/dev/null count=100
100+0 records in
100+0 records out
51200 bytes transferred in 1 secs (51200 bytes/sec)

What you can't do with /dev/null is set the immutable flag on it. That
way you won't be able to write to it.

-- 
Emmanuel Dreyfus.  
Avec Windows 3.1 ils etaient au bord du gouffre...
Avec Windows 95 ils ont fait un grand bon en avant.
manu@netbsd.org